title: Ghrelin: much more than a hunger hormone.
abstract: OBJECTIVE
  Ghrelin is a multifaceted gut hormone that activates its receptor, growth hormone secretagogue receptor (GHS-R). Ghrelin's hallmark functions are its stimulatory effects on growth hormone release, food intake and fat deposition. Ghrelin is famously known as the 'hunger hormone'. However, ample recent literature indicates that the functions of ghrelin go well beyond its role as an orexigenic signal. Here, we have reviewed some of the most recent findings on ghrelin and its signalling in animals and humans.
  
  
  RESULTS
  Ghrelin regulates glucose homeostasis by inhibiting insulin secretion and regulating gluconeogenesis/glycogenolysis. Ghrelin signalling decreases thermogenesis to regulate energy expenditure. Ghrelin improves the survival prognosis of myocardial infarction by reducing sympathetic nerve activity. Ghrelin prevents muscle atrophy by inducing muscle differentiation and fusion. Ghrelin regulates bone formation and metabolism by modulating proliferation and differentiation of osteoblasts.
  
  
  CONCLUSIONS
  In addition to ghrelin's effects on appetite and adiposity, ghrelin signalling also plays crucial roles in glucose and energy homeostasis, cardioprotection, muscle atrophy and bone metabolism. These multifaceted roles of ghrelin make ghrelin and GHS-R highly attractive targets for drug development. Ghrelin mimetics may be used to treat heart diseases, muscular dystrophy/sarcopenia and osteoporosis; GHS-R antagonists may be used to treat obesity and insulin resistance.
authors.affiliation: aUSDA/ARS Children's Nutrition Research Center, Department of Pediatrics bDivision of Diabetes, Endocrinology, and Metabolism, Department of Medicine cHuffington Center on Aging, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Geetali
authors.initials: G
authors.lastname: Pradhan
authors.forename: Susan L
authors.initials: SL
authors.lastname: Samson
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000818:Animals; D001066:Appetite / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004734:Energy Metabolism / Q000502:physiology; D054439:Ghrelin / Q000037:antagonists & inhibitors / Q000097:blood*; D005947:Glucose / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D006815:Hunger / Q000502:physiology*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D023421:Models, Animal; D009133:Muscular Atrophy / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism; D009765:Obesity / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology
chemical_list: D054439:Ghrelin; D007328:Insulin; D013006:Growth Hormone; D005947:Glucose